K 10
svn:author
V 6
jilles
K 8
svn:date
V 27
2013-04-07T15:26:09.707477Z
K 7
svn:log
V 533
mqueue,ksem,shm: Fix race condition with setting UF_EXCLOSE.

POSIX mqueue, compatibility ksem and POSIX shm create a file descriptor that
has close-on-exec set. However, they do this incorrectly, leaving a window
where a thread may fork and exec while the flag has not been set yet. The
race is easily reproduced on a multicore system with one thread doing
shm_open and close and another thread doing posix_spawnp and waitpid.

Set UF_EXCLOSE via falloc()'s flags argument instead. This also simplifies
the code.

MFC after:	1 week

END